HOUSTON, July 29: Discovery’s commander said on Friday that the shuttle’s crew had been surprised and disappointed to find that Nasa had not ended the foam debris problem that caused the Columbia disaster two years earlier. While the US space agency said it would only be able to give the shuttle the all-clear this weekend, it has expressed confidence that Discovery did not suffer serious damage. The crew on Friday pursued an operation to move 15 tons of equipment and supplies onto the International Space Station.

But it is also conducting a closer survey of the shuttle’s thermal shield to see if it suffered damage during Tuesday’s liftoff. Foam debris came off during the launch, prompting Nasa to suspend flights after Discovery’s return on Aug 7.

“We were actually quite surprised to hear we had some large pieces of debris fall off the external tank. It wasn’t what we had expected,” Commander Eileen Collins told US media in an interview from the shuttle. “Frankly, we were disappointed to hear that had happened.”

“I didn’t expect any large piece of foam to fall off the external tank. We thought we had this problem fixed.” Collins said she believed that Nasa experts could ‘fix’ the problem, but added that the agency had been right to suspend flights, even though the announcement was made while Discovery was still in space.

“What I’d like to say is this is something that has to be fixed,” Collins said. “I don’t think we should fly again unless we do something to prevent this from happening again.” A chunk of insulating foam fell off Columbia’s external fuel tank and punctured its outer skin, allowing superheated gases to get inside and causing the shuttle to break up in flames as it re-entered Earth’s atmosphere on Feb 1, 2003. All seven astronauts were killed and the shuttle programme was suspended until Discovery’s blastoff on Tuesday.

Nasa said on Thursday it would need three more days to finish its damage assessment. It acknowledged that shards of foam may have hit Discovery’s wing but said it was confident that Discovery was not at risk. Despite the flight suspension, the shuttle Atlantis is on standby to stage a rescue mission, if needed.

Steve Poulos, manager of the orbiter project office, said: “We are very confident that we are going to have a very clean vehicle that is going to be ready to re-enter.” Nasa experts identified 11 areas, including the wings, nose and belly, that they want examined again. Nine will be inspected Friday using a camera on an extension to the shuttle’s robotic arm.

Japanese astronaut Soichi Noguchi and American crewmate Stephen Robinson were to inspect two other areas on the leading edge of the shuttle’s wings during the mission’s first spacewalk Saturday.

Collins flipped the shuttle over as it approached the International Space Station on Thursday so two astronauts on board the station could inspect Discovery’s belly. All the images taken are now being examined at the Johnson Space Center in Houston, Texas.

Shuttle flight operations manager John Shannon said the images had not revealed any major damage. “Right now, we don’t see any significant gouges at all,” he told reporters. The crew has also begun moving about 15 tonnes of equipment and supplies from Discovery onto the space station.

Once that is finished, they will start moving about 13 tonnes of trash and discarded gear from the ISS back onto the shuttle. NASA said the waste accumulated over the past two and a half years had made living conditions cramped on the ISS.

American John Phillips and Russian Sergei Krikalev have been at the station since April. —AFP